The Model 6471 is Cat IV rated to 50V
and is over voltage protected to more than 250VAC against accidental
connection to live circuits. The voltage is also displayed on
screen. In the event of a system fault, the Model 6471 can withstand
250VAC.
Additional features of the Model 6471 include a heavy-duty field
case sealed against dust and water when closed (the test button is
also sealed against the elements); manual and automatic test
frequency selection from 41 to 513Hz; user selectable 3-Pole Fall of
Potential or 4-Pole Soil Resistivity test methods and user
selectable 2-Pole or 4-Pole Bond Resistance test method.
The Ground Resistance Tester Model 6471 is rugged, easy-to-use and
ideal for maintenance crews performing numerous tests. It exceeds
mechanical and safety specifications for shock, vibration and drop
tests per IEC standards. The adjustable test frequency provides for
rejection of high levels of interference, allowing it to be used
under difficult conditions such as high stray currents that affect
accuracy.

Touch and step potential testing
measurements. These tests are recommended when the ground cannot
be disconnected, where ground faults are highly likely to occur,
or when the “footprint” of grounded equipment (the outline
of the part of equipment in contact with the earth) is
comparable to the size of the ground to be tested.

2- or 4-Wire tests for continuity
tests on bonding or on grounding systems. This test is a DC
resistive test using 250mA or more and is used to check bonding
of all connection points on the ground system.

Earth coupling measurement and
display. Used to estimate the influence of two earth resistance
systems that are not connected to each other.